You could try coloring a bit more evenly. Of course it will be much easier if you’re using an alcohol-based marker (as opposed to Crayola) such as Copic or Ohuhu. If you need inspiration, I suggest to try checking out Appleminte’s videos on YouTube! It took a while for me to become the MaStEr ArTiSt (read: TRASH) I am today. In fact it took ten years. but thanks to lots of practice and YouTube vids, I’m much better than before. Also another tip: to create the daily habit of drawing every day, always force yourself to draw at least one thing per day. It can be a sketch or a doodle or anything. But I find that this habit has helped me prevent a “downward slide” in skills. Keep on trying and never give up!